jQuery Demo: Mad Libs Word Game

I am trying to come up with demos that will force me to learn the ins and outs of jQuery. For this demo, I have created a Mad Libs style game. If you did not use Mad Libs as a kid (what is wrong with you... j/k) it is a fill-in-the-blanks word game where not knowing the word context can lead to some whacky outcomes (and giggling fits). The whole idea behind jQuery: keep the output simple.

<span rel="madlib" type="noun" desc="A body part.">hand</span>. "Come on", she said, we have to

<span rel="madlib" type="verb" desc="A way to get from here to there.">run</span> to the

<span rel="madlib" type="noun" desc="A place.">lunch room</span> where we can eat lots of

<span rel="madlib" type="noun" desc="A food.">sandwhiches</span>! I

<span rel="madlib" type="adverb" desc="How you feel about something.">hate</span> those, he said, I would much rather

<span rel="madlib" type="verb" desc="Something you can do with your mouth.">eat</span> dog poop!

</p>

</div>

As you can see, I have created SPAN tags that relate to the Mad Lib game (rel="madlib"). Once the document loads, I use jQuery to dynamically loop through the document looking for these spans. Based on these spans, I create a FORM element and then create an input corresponding to each madlib span node.

Why do it this way? Because we don't care about the form - we care about the text. Doing it this way allows us to concentrate on getting some good Mad Libs text down on paper and not having to give the form a second thought.

Here is the jQuery code:

// This will fire when the document is ready.

$(

function(){

// Get a pointer to the mad libs container.

jMadLibsContainer = $( "#madlibs" );

// Get all of the madlib elements (defined by Span

// objects with the rel=madlib).

jMadLibs = $( "span[@rel='madlib']" );

// Create a form element and wire up the onsubmit

// to fire the show mad libs and then return false

// so that the form doesn't submit anywhere.

jMadLibsForm = $( "<form>" ).submit(

function(){

ShowMadLibs();

return( false );

}

);

// For each of the mad lib elements, we need to

// create a corresponding form element in our new form.

// Loop over each element and create the form fields.

jMadLibs.each(

// For each of the madlib nodes, we want to update

// the contents of the mad libs form.

function( intIndex ){

var jMadLibsNode = $( this );

jMadLibsForm.append(

"<p>" +

jMadLibsNode.attr( "type" ).toUpperCase() +

" : " +

jMadLibsNode.attr( "desc" ) +

"<br />" +

"<input type=\"text\" size=\"60\" />" +

"</p>"

);

}

);

// Add the submit button to the form.

jMadLibsForm.append(

"<p>" +

"<input type=\"submit\" value=\"Show Mad Libs!\" />" +

"</p>"

);

// Hide the mad lib container.

jMadLibsContainer.hide();

// Add the mad libs form after the mad libs container.

jMadLibsContainer.after(

jMadLibsForm

);

}

);

// This will be used to process the mad lib form once the

// user had entered all of the values.

function ShowMadLibs(){

var strErrors = "";

// Loop over the form elements to make sure that all

// the values have been entered.

jMadLibsForm.find( "input" ).each(

function( intIndex ){

var jPara = $( this.parentNode );

var jInput = jPara.find( "input" );

// Check to see if the form field is empty.

// If the input is empty, echo the field

// label and turn the field red.

if (jInput.val() == ""){

// Add the error text.

strErrors += (jPara.text() + "\n");

// Highlight the field.

jInput.css( "background-color", "#FFCCCC" );

} else {

// This field is fine, make sure that it

// is not hightlighted.

// Highlight the field.

jInput.css( "background-color", "#FFFFFF" );

}

}

);

// Check to see if we have any errors.

if (strErrors.length > 0){

// There were form validation errors. Alert them.

alert( strErrors );

} else {

// There were no form validation errors. Loop over

// each of the mad lib nodes and set the text.

jMadLibs.each(

function( intIndex ){

var jMadLibsNode = $( this );

// Set the text of the mad libs node to the

// form field valud of the input at the

// same index.

jMadLibsNode.text(

jMadLibsForm.find(

"p:nth-child(" + (intIndex + 1) + ") input"

).val()

);

}

);

// Hide the form.

jMadLibsForm.hide();

// Show the mad libs.

jMadLibsContainer.show();

}

}

// This is a collection that will store references to all of

// our Mad Lib DOM elements.

var jMadLibs = null;

// This is a pointer to the mad libs container. We just need

// something in which we can group all the editable content.

var jMadLibsContainer = null;

// This is a pointer to the mad libs form (yet to be created).

var jMadLibsForm = null;

It's not the shortest piece of jQuery in the world, but if you think about how dynamic this is and easy it makes updating the text, suddenly it doesn't seem like over kill by any means. This jQuery stuff is so crazy-cool. If you have not looked into it yet, do so now!

I am the co-founder and lead engineer at InVision App, Inc — the world's leading prototyping,
collaboration & workflow platform. I also rock out in JavaScript and ColdFusion 24x7 and I dream about
promise resolving asynchronously.